[PATCH 5.11 07/31] io_uring: refactor scheduling in io_cqring_wait

From: Greg Kroah-Hartman
Date: Fri Mar 19 2021 - 08:21:52 EST


From: Pavel Begunkov <asml.silence@xxxxxxxxx>

[ Upstream commit c1d5a224683b333ddbe278e455d639ccd4f5ca2b ]

schedule_timeout() with timeout=MAX_SCHEDULE_TIMEOUT is guaranteed to
work just as schedule(), so instead of hand-coding it based on arguments
always use the timeout version and simplify code.

Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/io_uring.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 68508f010b90..3e610ac062a3 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7226,9 +7226,8 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
.to_wait = min_events,
};
struct io_rings *rings = ctx->rings;
- struct timespec64 ts;
- signed long timeout = 0;
- int ret = 0;
+ signed long timeout = MAX_SCHEDULE_TIMEOUT;
+ int ret;

do {
io_cqring_overflow_flush(ctx, false, NULL, NULL);
@@ -7252,6 +7251,8 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
}

if (uts) {
+ struct timespec64 ts;
+
if (get_timespec64(&ts, uts))
return -EFAULT;
timeout = timespec64_to_jiffies(&ts);
@@ -7277,14 +7278,10 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
finish_wait(&ctx->wait, &iowq.wq);
continue;
}
- if (uts) {
- timeout = schedule_timeout(timeout);
- if (timeout == 0) {
- ret = -ETIME;
- break;
- }
- } else {
- schedule();
+ timeout = schedule_timeout(timeout);
+ if (timeout == 0) {
+ ret = -ETIME;
+ break;
}
} while (1);
finish_wait(&ctx->wait, &iowq.wq);
--
2.30.1